Package com.jogamp.newt.event
Class DoubleTapScrollGesture
java.lang.Object
com.jogamp.newt.event.DoubleTapScrollGesture
- All Implemented Interfaces:
GestureHandler
2 pointer scroll/rotate gesture handler processing
State ST_2PRESS_C merely exist to pick up gesture after one pointer has been lost temporarily.
MouseEvent
s
while producing MouseEvent.EVENT_MOUSE_WHEEL_MOVED
events if gesture is completed.
Criteria related to parameters:
- doubleTapSlop (scaled in pixels): - Max 2 finger distance to start 'scroll' mode - Max. distance diff of current 2-pointer middle and initiated 2-pointer middle. - touchSlop (scaled in pixels): - Min. movement w/ 2 pointer within ScaledDoubleTapSlop starting 'scroll' mode - Avoid computation if not within gesture, especially for MOVE/DRAG - Only allow gesture to start with PRESS - Leave gesture completely with RELEASE of both/all fingers, or dist-diff exceeds doubleTapSlop - Tolerate temporary lift 1 of 2 pointer - Always validate pointer-idImplementation uses a n-state to get detect gesture:
from | to | action |
---|---|---|
NONE | 1PRESS | 1-pointer-pressed |
1PRESS | 2PRESS_T | 2-pointer-pressed within doubleTapSlope |
2PRESS_T | SCROLL | 2-pointer dragged, dist-diff within doubleTapSlop and scrollLen >= scrollSlop |
2PRESS_C | SCROLL | 2-pointer dragged, dist-diff within doubleTapSlop |
SCROLL | SCROLL | 2-pointer dragged, dist-diff within doubleTapSlop |
isWithinGesture()
returns gestureState >= 2PRESS_C
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Nested Class Summary
Nested classes/interfaces inherited from interface com.jogamp.newt.event.GestureHandler
GestureHandler.GestureEvent, GestureHandler.GestureListener
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final float
Two pointer 'double tap' slop in millimeter, defaults to 20 mm.static final int
Two pointer 'double tap' slop in pixels (fallback), defaults to 104 pixels.static final float
Scroll threshold in millimeter, defaults to 3 mm.static final int
Scroll threshold in pixels (fallback), defaults to 16 pixels.Fields inherited from interface com.jogamp.newt.event.GestureHandler
DEBUG
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Constructor Summary
ConstructorsConstructorDescriptionDoubleTapScrollGesture
(int scaledScrollSlop, int scaledDoubleTapSlop) scaledScrollSlop < scaledDoubleTapSlop -
Method Summary
Modifier and TypeMethodDescriptionvoid
clear
(boolean clearStarted) Clears state of handler, i.e.Returns the correspondingInputEvent
for the gesture as detected by a previousGestureHandler.process(InputEvent)
, which has not beencleared
.final float[]
boolean
Returns true if a previousGestureHandler.process(InputEvent)
command produced a gesture, which has not beencleared
.boolean
Returns true if within a gesture as detected by a previousGestureHandler.process(InputEvent)
command, which has not beencleared
.boolean
process
(InputEvent in) Process the givenInputEvent
and returns true if it produced the gesture.toString()
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Field Details
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SCROLL_SLOP_PIXEL
public static final int SCROLL_SLOP_PIXELScroll threshold in pixels (fallback), defaults to 16 pixels. Can be overriden by integer propertynewt.event.scroll_slop_pixel
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DOUBLE_TAP_SLOP_PIXEL
public static final int DOUBLE_TAP_SLOP_PIXELTwo pointer 'double tap' slop in pixels (fallback), defaults to 104 pixels. Can be overriden by integer propertynewt.event.double_tap_slop_pixel
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SCROLL_SLOP_MM
public static final float SCROLL_SLOP_MMScroll threshold in millimeter, defaults to 3 mm. Can be overriden by integer propertynewt.event.scroll_slop_mm
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DOUBLE_TAP_SLOP_MM
public static final float DOUBLE_TAP_SLOP_MMTwo pointer 'double tap' slop in millimeter, defaults to 20 mm. Can be overriden by integer propertynewt.event.double_tap_slop_mm
.
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Constructor Details
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DoubleTapScrollGesture
public DoubleTapScrollGesture(int scaledScrollSlop, int scaledDoubleTapSlop) scaledScrollSlop < scaledDoubleTapSlop- Parameters:
scaledScrollSlop
- Distance a pointer can wander before we think the user is scrolling in pixels.scaledDoubleTapSlop
- Distance in pixels between the first touch and second touch to still be considered a double tap.
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Method Details
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toString
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clear
public void clear(boolean clearStarted) Description copied from interface:GestureHandler
Clears state of handler, i.e. resets all states incl. previous detected gesture.- Specified by:
clear
in interfaceGestureHandler
- Parameters:
clearStarted
- if true, also clearsstarted
state, otherwise stay within gesture - if appropriate. Staying within a gesture allows fluent continuous gesture sequence, e.g. for scrolling.
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isWithinGesture
public boolean isWithinGesture()Description copied from interface:GestureHandler
Returns true if within a gesture as detected by a previousGestureHandler.process(InputEvent)
command, which has not beencleared
. Otherwise returns false.- Specified by:
isWithinGesture
in interfaceGestureHandler
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hasGesture
public boolean hasGesture()Description copied from interface:GestureHandler
Returns true if a previousGestureHandler.process(InputEvent)
command produced a gesture, which has not beencleared
. Otherwise returns false.- Specified by:
hasGesture
in interfaceGestureHandler
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getGestureEvent
Description copied from interface:GestureHandler
Returns the correspondingInputEvent
for the gesture as detected by a previousGestureHandler.process(InputEvent)
, which has not beencleared
. Otherwise returns null.Only implemented for gestures mapping to
InputEvent
s.- Specified by:
getGestureEvent
in interfaceGestureHandler
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getScrollDistanceXY
public final float[] getScrollDistanceXY() -
process
Description copied from interface:GestureHandler
Process the givenInputEvent
and returns true if it produced the gesture. Otherwise returns false.If a gesture was already detected previously and has not been cleared, method does not process the event and returns true.
Besides validation of the event's details, the handler may also validate the
InputEvent.InputClass
and/orInputEvent.InputType
.- Specified by:
process
in interfaceGestureHandler
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